Nuclear Deterrent

Why did the Warsaw Pact not use nuclear weapons to attack NATO?

If the Soviet Union, which made up the largest part of the Warsaw Pact forces had thousands of nuclear weapons available to use against NATO, why did it not use them?

Were they afraid that NATO would use nuclear weapons in retaliation?

Were they afraid that their Warsaw Pact allies might object to the use of nuclear weapons and refuse to fight?

Would there be much point in winning a war against NATO that would gain land that had been turned into a radio-active wasteland?

A former American President Jimmy Carter issued a grave warning when he pointed out that if the Soviet Union and NATO resorted to nuclear war "more destructive power than in the entire 1939-1945 war would be unleashed every second for the long afternoon it would take for all the bombs and missiles to fall." To put it another way, the amount of high explosive detonated in World War Two was about 3,000,000 tons (3 Mega tons). The Soviet Union and the NATO allies had between them nuclear weapons which had the explosive power of about 7,400 Mega tons, that is just about two thousand five hundred times the total used in World War Two.

The reason - Mutually Assured Destruction

Mutually Assured destruction (MAD) was the idea whereby to launch a nuclear attack against another nuclear-armed power would result in the annihilation of both. Knowing that launching such an attack would result in your own destruction through the enemy's nuclear retaliation was considered a powerful deterrent to the use of nuclear weapons in the first place.